Set tab stops at columns n1, n2, ... The leftmost
column is the column 1. n2 and the rest of the list can be of
the form `+num', in which case it specifies the increment from
the tab stop last specified by the list.

-n

Set tab stops at every n columns. For most of the
terminals, the standard tab stop setting is the equivalent of
`-8'.

-code

--code=code

-C code

Set tab stops using one of the "canned" specification. The
second and the third formats are useful if the name of the canned
specification conflicts with one of the long options supportred
by GNU tabs.

--filename

--file=filename

--F filename

Read the first line of filename, find parameters separated
by blanks enclosed by <: and :> on that line, find
a parameter that begins with t, and then use it as tab
specification. If any of the above steps fails, set tab stops to
every 8 columns. The second and the third formats are useful if
the name of the file conflicts with one of the long options
supportred by GNU tabs.